The versatile transcription factor Oct-1 : a crucial protein in embryonic development and a key component of the stress cellular response

Dalvai, Mathieu.
The versatile transcription factor Oct-1 : a crucial protein in embryonic development and a key component of the stress cellular response.
2008,
PhD Thesis, University of Basel,
Faculty of Science.

Abstract

Oct-1 is a transcription factor belonging to the POU family (Clerc et al. 1988) (Herr et al. 1988) (Ryan and Rosenfeld 1997). The members of this family are involved in a broad range of biological processes like transcription of housekeeping genes (Oct-1), pluripotency of embryonic stem cells (Oct-4) or development of immune system (Oct-1, Oct-2) (Spaniol et al. 1996). The transcription factor Oct-1 is ubiquitously expressed in embryonic and adult tissues, and regulates the expression of a variety of genes. Previous studies described Oct-1 to be regulated at the protein level by phosphorylation in a cell cycle dependent manner. In addition, more recently it has been shown that Oct- 1 is induced in response to DNA damage and modulates the activity of genes like GADD45 important for the cellular stress response (Segil et al. 1991) (Zhao et al. 2000) (Jin et al. 2001) (Fan et al. 2002) (Tantin et al. 2005).. Knockout and a conditional oct-1 knockout alleles were created in our laboratory, and used to generate Oct-1 deficient mouse embryonic fibroblast (MEFs) and embryonic stem cells (ES). We used them as a model to study the cellular response to stress in absence of Oct-1. We have found that cells lacking Oct-1 were less sensitive to stress like